Does it worth the effort to promote apps to other developers?

I’m wondering whether it worth to try to promote our app to other developers (say on developer’s forum, blogs, G+ groups, FB groups, whatever cross your mind).

After all almost none of them are the target public of your app / game.

What’s your experience? Does it really worth the effort? I mean, extra 100 or 500 downloads after posting to a lot of places full of developers won’t py neither the time nor the effort to promote the app. Aren’t they more interested into invest their time promoting and developing their own apps then downloading someone else app?

Or am I wrong?

I’d love to hear your experience on this subject.

Note: I’m not talking about reviews exchange, translations exchange, helping / asking for help regarding bugs and other interactions like that. These type of interactions are really fruitful. I’m talking about promoting apps to developers you have no kind of contact. You just want to let them aware of your app in the hope they will download and enjoy your work.

I don’t feel it is worth the time too.

We usually exchange installs with other developers. It takes too much time and it is not easy to find a developer that can cooperate with you long time. But we keep this way to promote.